scholarly journals Intestinal NF-κB and STAT signalling is important for uptake and clearance in a Drosophila-Herpetomonas interaction model

2018 ◽  
Author(s):  
Lihui Wang ◽  
Megan A. Sloan ◽  
Petros Ligoxygakis

ABSTRACTDipteran insects transmit diseases to humans, often in the form of trypanosomatid parasites. To accelerate research in more difficult contexts of dipteran-parasite relationships, we studied the interaction of the model dipteran Drosophila melanogaster and its natural trypanosomatid Herpetomonas muscarum. Parasite infection reduced fecundity but not lifespan in NF-κB/Relish-deficient flies. Gene expression analysis implicated the two NF-κB pathways Toll and Imd as well as STAT signalling. Tissue specific knockdown of key components of these pathways in enterocytes (ECs) and intestinal progenitor cells influenced initial numbers, infection dynamics and time of clearance. Herpetomonas triggered STAT activation and proliferation of Intestinal Stem Cells (ISCs). Loss of Relish suppressed the latter, resulting in increased parasite numbers and delayed clearance. Finally, loss of Toll signalling decreased EC numbers and enabled parasite persistence. This network of signalling may represent a general mechanism of the dipteran early response to trypanosomatids, crucial for parasite establishment and therefore transmission.AUTHOR SUMMARYNeglected Tropical Diseases are the most common diseases of the world’s poorest people. Many are caused by parasites called trypanosomatids that are transmitted to humans via insects belonging to the order of Diptera (also known as true flies). These flies (including tsetse, sand flies and black flies) are difficult to study in the lab and so the prospect of rapid progress in the basic biology of fly-parasite interaction is bleak. However, a model dipteran species with an extensive “tool-box” is the fruit fly Drosophila melanogaster with its natural trypanosomatid Herpetomonas muscarum. Here we establish the framework of their early interaction with the view that part of this interaction will represent an evolutionary conserved component of the dipteran response to parasite infection and will inform more targeted studies into medically important but difficult to study Diptera.

2019 ◽  
Author(s):  
Megan A. Sloan ◽  
Karen Brooks ◽  
Thomas D. Otto ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  

AbstractTrypanosomatid parasites are causative agents of important human and animal diseases such as sleeping sickness and leishmaniasis. Most trypanosomatids are transmitted to their mammalian hosts by insects, often belonging to Diptera (or true flies). These are called dixenous trypanosomatids since they infect two different hosts, in contrast to those that infect just insects (monoxenous). However, it is still unclear whether dixenous and monoxenous trypanosomatids interact similarly with their insect host, as fly-monoxenous trypanosomatid interaction systems are rarely reported and under-studied – despite being common in nature. Here we present the genome of monoxenous trypanosomatidHerpetomonas muscarumand discuss its transcriptome duringin vitroculture and during infection of its natural insect hostDrosophila melanogaster. TheH. muscarumgenome is broadly syntenic with that of human parasiteLeishmania major. We also found strong similarities between theH. muscarumtranscriptome during fruit fly infection, and those ofLeishmaniaduring sand fly infections. Overall this suggestsDrosophila-Herpetomonasis a suitable model for less accessible insect-trypanosomatid host-parasite systems such as sandfly-Leishmania.Author SummaryTrypanosomes andLeishmaniaare parasites that cause serious Neglected Tropical Diseases (NTDs) in the world’s poorest people. Both of these are dixenous trypanosomatids, transmitted to humans and other mammals by biting flies. They are called dixenous as they can establish infections in two different types of hosts – insect vectors and mammals. In contrast, monoxenous trypanosomatids usually only infect insects. Despite establishment in the insect’s midgut being key to transmission of NTDs, events during early establishment inside the insect are still unclear in both dixenous and monoxenous parasites. Here, we study the interaction between a model insect – the fruit flyDrosophila melanogaster– and its natural monoxenous trypanosomatid parasiteHerpetomonas muscarum. We show that both the genome of this parasite, and gene regulation at early stages of infection have strong parallels withLeishmania. This work has begun to identify evolutionarily conserved aspects of the process by which trypanosomatids establish in insects, thus potentially highlighting key checkpoints necessary for transmission of dixenous parasites. In turn, this might inform new strategies to control trypanosomatid NTDs.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rachel Paul ◽  
Guillaume Giraud ◽  
Katrin Domsch ◽  
Marilyne Duffraisse ◽  
Frédéric Marmigère ◽  
...  

AbstractFlying insects have invaded all the aerial space on Earth and this astonishing radiation could not have been possible without a remarkable morphological diversification of their flight appendages. Here, we show that characteristic spatial expression profiles and levels of the Hox genes Antennapedia (Antp) and Ultrabithorax (Ubx) underlie the formation of two different flight organs in the fruit fly Drosophila melanogaster. We further demonstrate that flight appendage morphology is dependent on specific Hox doses. Interestingly, we find that wing morphology from evolutionary distant four-winged insect species is also associated with a differential expression of Antp and Ubx. We propose that variation in the spatial expression profile and dosage of Hox proteins is a major determinant of flight appendage diversification in Drosophila and possibly in other insect species during evolution.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaochan Xu ◽  
Wei Yang ◽  
Binghui Tian ◽  
Xiuwen Sui ◽  
Weilai Chi ◽  
...  

AbstractThe fruit fly, Drosophila melanogaster, has been used as a model organism for the molecular and genetic dissection of sleeping behaviors. However, most previous studies were based on qualitative or semi-quantitative characterizations. Here we quantified sleep in flies. We set up an assay to continuously track the activity of flies using infrared camera, which monitored the movement of tens of flies simultaneously with high spatial and temporal resolution. We obtained accurate statistics regarding the rest and sleep patterns of single flies. Analysis of our data has revealed a general pattern of rest and sleep: the rest statistics obeyed a power law distribution and the sleep statistics obeyed an exponential distribution. Thus, a resting fly would start to move again with a probability that decreased with the time it has rested, whereas a sleeping fly would wake up with a probability independent of how long it had slept. Resting transits to sleeping at time scales of minutes. Our method allows quantitative investigations of resting and sleeping behaviors and our results provide insights for mechanisms of falling into and waking up from sleep.


1999 ◽  
Vol 19 (2) ◽  
pp. 1159-1170 ◽  
Author(s):  
Madeline A. Crosby ◽  
Chaya Miller ◽  
, Tamar Alon ◽  
Kellie L. Watson ◽  
C. Peter Verrijzer ◽  
...  

ABSTRACT The genes of the trithorax group (trxG) inDrosophila melanogaster are required to maintain the pattern of homeotic gene expression that is established early in embryogenesis by the transient expression of the segmentation genes. The precise role of each of the diverse trxG members and the functional relationships among them are not well understood. Here, we report on the isolation of the trxG gene moira(mor) and its molecular characterization. morencodes a fruit fly homolog of the human and yeast chromatin-remodeling factors BAF170, BAF155, and SWI3. mor is widely expressed throughout development, and its 170-kDa protein product is present in many embryonic tissues. In vitro, MOR can bind to itself and it interacts with Brahma (BRM), an SWI2-SNF2 homolog, with which it is associated in embryonic nuclear extracts. The leucine zipper motif of MOR is likely to participate in self-oligomerization; the equally conserved SANT domain, for which no function is known, may be required for optimal binding to BRM. MOR thus joins BRM and Snf5-related 1 (SNR1), two known Drosophila SWI-SNF subunits that act as positive regulators of the homeotic genes. These observations provide a molecular explanation for the phenotypic and genetic relationships among several of the trxG genes by suggesting that they encode evolutionarily conserved components of a chromatin-remodeling complex.


2005 ◽  
Vol 83 (2) ◽  
pp. 368-371 ◽  
Author(s):  
Mark J Fitzpatrick ◽  
Evelyn Szewczyk

Denticles are small projections on the underside of larval fruit flies that are used to grip the substrate while crawling. Previous studies have shown that (i) there is natural variation in denticle number and pattern between Drosophila melanogaster (Meigen, 1830) and several closely related species and (ii) mutations affecting denticle morphology have negative effects on locomotory performance. We hypothesized that there would be a correlation between denticle number and locomotory performance within populations of D. melanogaster. Despite finding considerable variation in denticle number, we found no correlation between denticle number and three measurements of larval locomotion: speed, acceleration, and absolute turning rate.


2003 ◽  
Vol 71 (6) ◽  
pp. 3540-3550 ◽  
Author(s):  
Marc S. Dionne ◽  
Nafisa Ghori ◽  
David S. Schneider

ABSTRACT Mycobacterium marinum is a pathogenic mycobacterial species that is closely related to Mycobacterium tuberculosis and causes tuberculosis-like disease in fish and frogs. We infected the fruit fly Drosophila melanogaster with M. marinum. This bacterium caused a lethal infection in the fly, with a 50% lethal dose (LD50) of 5 CFU. Death was accompanied by widespread tissue damage. M. marinum initially proliferated inside the phagocytes of the fly; later in infection, bacteria were found both inside and outside host cells. Intracellular M. marinum blocked vacuolar acidification and failed to colocalize with dead Escherichia coli, similar to infections of mouse macrophages. M. marinum lacking the mag24 gene were less virulent, as determined both by LD50 and by death kinetics. Finally, in contrast to all other bacteria examined, mycobacteria failed to elicit the production of antimicrobial peptides in Drosophila. We believe that this system should be a useful genetically tractable model for mycobacterial infection.


2010 ◽  
Vol 72 (4) ◽  
pp. 231-234 ◽  
Author(s):  
James Billingsley ◽  
Kimberly A. Carlson

Do our genes exclusively control us, or are other factors at play? Epigenetics can provide a means for students to use inquiry-based methods to understand a complex biological concept. Students research and design an experiment testing whether dietary supplements affect the lifespan of Drosophila melanogaster over multiple generations.


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